The current state of the art for the enhancement of haze in Si Tandem systems is based upon surface engineering approaches to texturize either the TCO surface and/or the glass surface prior to TCO deposition. By creating large faceted surface features on the TCO, incoming light will geometrically scatter into the underlying semiconductor. This leads to increased light trapping, overcoming the poor absorption coefficient in Si. Because TCO growth is conformal in nature, the creation of texture on the glass surface can lead to the same scattering phenomena, therefore increasing the level of light trapping in the Si.
In CdTe systems, a low haze TCO is generally achieved through the smoothing of the film surface, either by post growth polishing and/or deposition process modifications. Both of these paths add additional process complexity, not to mention cost in the case of post polishing.
It would be advantageous to have a smooth TCO surface with no post growth processing and a largely tunable haze value.